NASA’s Perseverance rover discovered unexpected igneous rocks in Mars’ Jezero Crater, where scientists had expected sedimentary rocks formed along the shoreline of an ancient lake.

The rocks contained carbonate minerals and provided evidence that water interacted with them on at least three separate occasions, repeatedly changing their chemistry and appearance.

Scientists used Perseverance’s SuperCam instrument to analyze more than 185 bedrock targets, using laser-generated plasma to determine the rocks’ chemical composition.

The findings challenge the earlier belief that the carbonate deposits formed primarily through interaction with Jezero Crater’s ancient lake, NASA has reported.

Researchers say the Margin Unit appears to have been a crossroads for multiple water systems, offering broader clues about Mars’ watery past and its potential to preserve evidence of ancient microbial life.